1. Field of the Invention
This system pertains to compact digital disc systems. In particular, this invention directs itself to microprocessor controlled compact digital disc systems adapted for providing an interactive teaching operational mode in addition to an entertainment operational mode. More in particular, this invention pertains to a compact digital disc system where a keyboard is provided for interaction with the system during the teaching mode of operation. More in particular, this invention pertains to a compact digital disc system where the keyboard provided for use in the teaching mode includes a removable graphic overlay for referencing each of the keyboard keys to a specific lesson plan. Additionally, the subject invention relates to compact digital disc systems having keyboards for use in an interactive teaching mode where each keyboard switch relates to a unique character code which identifies a predetermined location in a look-up table. Still further, this invention relates to compact digital disc systems using a random access memory for the temporary storage of the unique character code generated in response to the operation of a keyboard switch. Further, this invention relates to a compact disc system utilizing a read only memory to provide a look-up table for cross referencing a unique character code generated in response to a keyboard switch operation to a predetermined aural response stored on a compact digital disc.
2. Prior Art
Compact digital disc systems which are directed to providing an audio output for entertainment purposes are known in the art. Additionally, audio teaching machines having keyboards with graphic overlays are also known in the art. However, such prior art audio teaching devices do not have the ability to randomly access a discrete previously stored variable length audio data in response to a particular keyboard entry. In addition, teaching devices do not generally store the audio output data in a format compatible with entertainment material and devices which utilize the same storage media. In opposition, the subject system is not limited to functioning as either an entertainment system or a teaching system, but functions as either operating mode. Thus, the subject invention has greater utilization as compared with those prior art systems and provides a cost effective means of providing both functions.
The best prior art known to Applicant includes U.S. Pat. Nos. 4,245,404; 3,913,443; 4,495,608; 3,724,100; 4,484,328; 4,380,438; 3,795,989; 3,996,671; 3,947,972; 4,001,947; 3,659,030; 3,648,385; 4,523,304; 4,552,535; 3,702,302; 3,689,930; 3,775,864; 4,464,124; 4,027,405; and, 3,886,671.